you should talk 2 her at least once every other day unless u c her often
as much as you would to any other person!
talk to them both.
you should hang out with him more often
Try to talk to the girl before he does to see if you have a chance with her.
Talk to your cousin about this.
It depends on if she likes you and if she does talk about dating
Like she is a person. (she is one, after all!) After that the rest is up to you.
ask her out, or start simple and just talk to her
Things she likes to talk about
move on, she's not interested
you should probobly find another girl
If it is your first conversation with her you should engage her with small talk